As a reaction to a spell being cast, you absorb the magic being woven into the spell. If the spell is 3rd level or lower, the spell fails and has no effect. If the spell is of a higher level, it is unaffected.

The next time you cast a spell of 1st level or higher before you finish a short or long rest, that spell is cast as if using a spell slot one level higher. If you currently are benefitting from this effect, you cannot gain the benefit again.

At Higher Levels. If you cast this spell using a spell slot of 5th level or higher, the interrupted spell has no effect if its level is less than the level of the spell slot you used.